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What are you trying to do, exactly? The term "concat" means to join several files, but you are only referring to one input, output1.mp4, and one output, i0.ts. Encoding to ts output container will use the mpeg2video encoder by default (at least with your build), and last time I checked the default bitrate or quality setting for this encoder is -b:v 200k which is too low for most cases.
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LordNeckbeardJun 13 '13 at 17:15

sorry. Then i concat them with ffmpeg -i "concat:i0.ts|i1.ts" output1111.mp4. But the problem is that the quality is bad already when i make ts-files
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jeniaJun 13 '13 at 17:34

You may not need to re-encode to MPEG-2 video. Do all of your original inputs (output1.mp4, etc) have the same formats, frame rate, and frame size?
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LordNeckbeardJun 13 '13 at 18:10